Which quadratic equation is equivalent to [tex](x+2)^2 + 5(x+2) - 6 = 0[/tex]?

A. [tex](u+2)^2 + 5(u+2) - 6 = 0[/tex] where [tex]u = (x - 2)[/tex]

B. [tex]u^2 + 4 + 5u - 6 = 0[/tex] where [tex]u = (x - 2)[/tex]

C. [tex]u^2 + 5u - 6 = 0[/tex] where [tex]u = (x + 2)[/tex]

D. [tex]u^2 + u - 6 = 0[/tex] where [tex]u = (x + 2)[/tex]



Answer :

Sure, let's solve this step by step!

We are given the quadratic equation:

[tex]$(x + 2)^2 + 5(x + 2) - 6 = 0.$[/tex]

We want to find an equivalent form of this equation by making a substitution.

1. Substitution Step:
We will let [tex]\( u = x + 2 \)[/tex].

2. Rewrite the Equation:
Substitute [tex]\( u \)[/tex] in place of [tex]\( x + 2 \)[/tex] in the given equation:
[tex]$(u)^2 + 5(u) - 6 = 0.$[/tex]

3. Simplify:
Simplify the equation:
[tex]$u^2 + 5u - 6 = 0.$[/tex]

Hence, the quadratic equation equivalent to [tex]\((x + 2)^2 + 5(x + 2) - 6 = 0\)[/tex] after making the substitution [tex]\( u = x + 2 \)[/tex] is:

[tex]$u^2 + 5u - 6 = 0.$[/tex]

So, the correct answer to the given question is:

[tex]$u^2 + 5u - 6=0 \quad \text{where} \quad u=(x+2).$[/tex]